Monoesters of phosphonic acids and alkali metal or alkaline earth metal salts thereof



United States Patent MONOESTERS 0F PHOSPHONIC ACIDS AND AL- KALI METAL0R ALKALINE EARTH METAL SALTS THEREOF Emile Cherbuliez and JosephRabinowitz, Geneva, Switzerland, assignors to Hooker ChemicalCorporation, Niagara Falls, N.Y., a corporation of New York No Drawing.Filed Nov. 24, 1965, Ser. No. 509,649

4 Claims. (Cl. 260-958) This is a continuation-in-part of United Statespatent application Ser. No. 230,315, filed Oct. 11, 1962, now US. PatentNo. 3,268,629.

The present invention relates to new phosphonic monoesters and to animproved process for making phosphonic monoesters. According to theinvention, an alcohol is reacted with an anhydride of a phosphonic acidto produce phosphonic monoesters of high purity in very good yields.

As anhydrides of phosphonic acids there are preferably used thosecommonly known as phosphonic oxides. These anhydrides can be prepared byknown methods, as for example, by the action of the dichloride of aphosphonic acid according to the equation:

in which R represents an aliphatic, aromatic or heterocyclic radical,usually of 1 to 18 carbon atoms, most often of 2 to carbon atoms; theseradicals may be substituted, as for example, with a nitro group or ahalogen atom, such as fluorine. The radical R may more especially berepresented by a monocyclic aryl radical, such as the phenyl,halogeno-phenyl, e.g., p-fiuoro-phenyl, p-chloro-phenyl, p-bromo-phenylor nitro-phenyl, e.g. pnitro phenyl radical.

As a phosphonating agent, one may also use polyphosphonic acids, thatis, the partial anhydrides of phosphonic acids, which give a lesseryield of ester, but which permit the recovery, in the form of alkalineearth metal phosphonate, of the phosphonic acid which did not react andwhich may thus be used for another charge. The polyphosphonic acids areconsidered to be phosphonic anhydrides.

The polyphosphonic acids are obtained by heating correspondingphosphonic acids at a temperature between about 120 to 200 degreescentigrade and under vacuum (about 3 to 30 millimeters of mercury) for aperiod of about 48 to 96 hours. The pyrophosphonic acids may also beprepared by the action of a given quantity of water on correspondingdichlorides.

It is sufficient to mix an equivalent of phosphonic oxide (RPO with 0.5to 3 moles, especially with 1.2 to 3 moles of anhydrous R OH alcohol(excess alcohol) and to heat the mixture for a period of 3 to 48 hoursat temperatures of between and 200 degrees centigrade, preferablybetween 50 and 150 degrees centrigrade, and the reaction may also becarried out under vacuum. The mixture becomes homogeneous and thephosphonic monoester is obtained, as exemplified by the followingequation:

Generally, the phosphonic monoester is separated from the mixture in theform of its salt which may be char acterized by the formula In the aboveformulas, R has the significance indicatet previously, R representsaliphatic radicalssuch as alkyl alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl or bicycloalkyl, araliphatic radicals such asaralkyl, aro matic radicals such as aryl, and heterocyclic radicals, Mis a metal selected from the group consisting of alkal. and alkalineearth metals, and n is greater than one. These radicals, including thosewhich contain double or triple bonds, remain intact during the reaction.The straight chain saturated aliphatic radicals usually are of 1 to 18carbon atoms, preferably from 1 to 8 carbon atoms, the straight chainunsaturated aliphatic radicals usually are of 2 to 18 carbon atoms,preferably from 2 to 8 carbon atoms, while the cycloaliphatic radicalsare from 3 to 18, preferably from 3 to 12. The radicals R may also carryone or more compatible substituents such as halogen atoms, particularlychlorine or fluorine, free or esterified hydroxyl or carboxyl groups,carboxamide, nitrile or amino groups, preferably tertiary-substitutedamino groups of nitrogen atoms, for example, aliphatic radicals such asmethyl or ethyl groups or aromatic or araliphatic radicals such as aphenyl or benzyl radical. These substituents may be found in anycompatible position of the indicated radicals with respect to the OH tobe phosphonated.

Thus, this reaction is a general one and applies to various alcoholtypes. If a polyol is treated by a phosphonic oxide, only one functionalOH is phosphonated, whatever the quantity of oxide is used. Among thepolyols are glycerol, glycol, pentaerythritol, neopentyl glycol,1,4-(hydroxymethyl)benzene, sorbitol and trimethylol propane. With thehalogenated alcohols, and particularly with the chlorinated andfiuorinated alcohols, the reaction is carried out quite normally and thehalogen is retained. With the amino alcohols this reaction proceedsquite Well When the amino function is tertiary. Despite the fact thatthe phenylphosphonic oxide has a tendency to react with primary andsecondary amines to yield phosphonic amides, there are obtainedphosphonic monoesters of amino alcohols With unreacted primary orsecondary amino groups and only a minimal percentage of phosphonicamide. This amidized group may, if desired, be readily hydrolyzed in anacid medium when the ester portion is relatively stable. Thephosphonation reaction is also readily accomplished and in good yieldwith unsaturated alcohols having do-uble or triple bonds, singly or inmultiple. The reaction is more rapid with primary than with secondaryalcohols, thus, heating for a longer time will be desirable duringphosphonation of a secondary alcohol.

A preferred embodiment of this invention is the reaction of an alcoholwith an anhydride of a phosphonic acid in the presence of a tertiarybase, such as tri-lower alkylamine, e.g., triethylamine ortrimethylamine or a cyclic tertiary base, such :as pyridine. Theaddition of an equivalent of the said tertiary base is especiallyadvantageous if the radical R is the radical of a tertiary aliphaticalcohol or the radical of an alcohol sensitive to acid, such as aterpene alcohol.

If the radical R is the radical of an a-nitrilo alcohol, the nitrilegroup may be hydrolyzed to form an ester of an a-carboxamido alcohol. Ifthe reaction mixture does not contain any water, there may beintermediate formation of a cyclic derivative of the ester, which iseasily ydrolyzed with water to form the monoester of the carboxamidoalcohol. With {3-, 'yand fi-nitrilo alcohols 1e monoesters of thenitrilo alcohols are preferably stained; the hydrolysis to thecarboxamido derivative oes not take place.

The monoesters obtained can be isolated as their metal llts. Thealkaline or alkaline earth metal salts of phoshonic monoesters arepractically neutral in aqueous Jlution (pH about 6) and can be preservedindefinitely 1 aqueous solution (at this pH the time of half-hydrolysis1 a 0.1 molar aqueous solution of ester at 100 degrees entrigrade isgreater than 500 hours); the salts of phoshonic monoesters of aminoalcohols are alkaline in queous solution (pH 105-11) and also are stableat his pH.

In order to isolate the alkaline earth metal or alkali metal salts ofthe phosphonic monoester, including the alcium, barium, strontium,sodium, potassium, lithium, .luminum and magnesium salts, one proceedsas follows:

After cooling, the excess alcohol is distilled (when a arge excess isused) under vacuum. The residue is taken 1p by Water and neutralized bya hydroxide of an alkaline :arth metal to a pH of 8.2 (turning ofphenolphthalein). In the case of amino alcohols, it is desirable to addhyiroxide sufficient to obtain a pH of about 11.) The phosghonic acidwhich may still be present (formed by hyrlrolysis of the oxide which maynot have reacted, or formed in the course of the reaction whenpolyphosphonic acid is used) precipitates partially as an alkaline earthmetal salt; it is completely precipitated by the addition of one volumeof alcohol. This is filtered and the filtrate which contains thealkaline earth metal salt of the phosphonic monoester is evaporated anddried under vacuum. Generally, the product obtained is pure. If not, itis purified by extraction with boiling acetone (which dissolves theimpurities); after cooling, the alkaline earth metal salt of thephosphonic monoester is filtered.

If it is desired to obtain alkali metal salts of these monoesters, thealkaline earth metal salt is dissolved in water and there is added therequired quantity of carbonate of an alkali metal. The precipitate ofthe alkaline earth metal carbonate formed is filtered off and thefiltrate is evaporated to dryness under vacuum. The amorphous residuetreated by acetone is transformed into a crystalline precipitate whichis the alkali metal salt of the monoester. One may adapt the abovemethods to make other salts.

The alkaline earth metal salts of the phosphonic monesters of superioraliphatic alcohols or of terpene alcohols are generally insoluble inwater or in 50 percent ethyl alcohol. In order to isolate thesemonoesters, one proceeds preferably as follows:

(a) After cooling, the reaction mass is taken up by ether andneutralized by triethylamine. The triethylammonium salt of thephosphonic acid is filtered off, whereas the triethylammoniurn salt ofthe phosphonic monoester is soluble. The ether and the excess of thetertiary base are distilled, the residue is taken up by ether and thealkali earth metal salt of the phosphonic monoester is precipitated byadding an aqeuous solution of the corresponding alkali earth metalhalogenide. The precipitate is washed with water and is purified aspreviously described.

(b) If the reaction is carried out in the presence of a tertiary basesuch as trimethylamine, triethylamine or pyridine, the reaction mixtureis taken up by ether and the phosphonate of the tertiary amine isfiltered off. The ether and the excess of the tertiary base aredistilled and the residue is taken up by water. The alkaline earth metalsalt of the phosphonic monoester is precipitated by adding an aqueoussolution of an alkali earth metal halogenide.

If the free phosphonic monoester crystalilzes easily, the reactionmixture is taken up by water and the free phosphonic monoester isprecipitated by adding a strong acid,

such as hydrochloric acid (this is the case, for instance, of menthylphenylphosphonic acid).

This new process of phosphonation of alcohols by phosphonic oxides andpolyphosphonic acids has a number of advantages: it leads straight tomonoesters only, it is simple and directly gives pure products in veryhigh yield, calculated as a percentage of the theoretical value.Moreover, the process is quite general and many of the preparedphosphonic monoesters are new.

The monoesters thus obtained and their salts may be used as additives toliquid fuels, such as gasoline, or as products for impregnating fibersso as to make them fireproof, pest-resistant or vermin-proof.

The invention is illustrated but not limited by the following examples.All parts are by weight and all temperatures are in degrees centigrade,unless otherwise indicated.

Example 1 140 parts (1 equivalent) of phenylphosphonic oxide (C H 'POand 48 to 64 parts (1.5 to 2 moles) of anhydrous methanol are heated to100 degrees centigrade (bath temperature). After cooling, the excessalcohol is evaporated under vacuum and the residue is taken up with 500to 800 parts of H 0. This solution is neutralized by Ca(OH) (or Ba(OH)if one desires to obtain a barium salt of the monoester) up to a pH atwhich phenolphthalein turns to colored form (about 8.2). Then an equalvolume of alcohol is added and the calcium (or barium) phenylphosphonatethus precipitated is filtered. The filtrate, evaporated to dryness,yields the monomethylphenylphosphonate of calcium (or barium) which isgenerally pure initially. If it is not, the dry residue is dissolved inboiling acetone and, after cooling, the calcium or barium monomethylphenylphosphonate is filtered. The yield in pure product,

is 77 percent of theoretical.

Instead of phenylphosphonic oxide, other aryl phospllonic oxides may beemployed to obtain corresponding salts of aryl phosphonie monoesters.

Example 2 The phenylphosponic monoesters (in the form of their calciumor barium salts) of the alcohols mentioned below have been prepared inthe same manner as described in Example 1.

The monoester of ethanol of the formula:

It) OM O 0H5PO C2115 Yield=84 percent.

The monoester of propanol of the formula:

0 OM II/ C u 1 -0 011291120 H3 Yield= percent.

The monoester of isopropanol of the formula:

H/ CuH5 z)z Yield=56 percent.

The monoester of butanol of the formula:

0 0M CfiH5P-OCII2CII2C I2CII3 Yield=75 percent.

The monoester of isobutanol of the formula:

Yield=71 percent.

In all the above formulas M is C21 or Ba Example 3 The esters describedin Examples 1 and 2 were also obtained with the aid ofpolyphenylphosphonic acid (ft-2) as the phosphonating agent, in thefollowing manner:

In a flask connected to a water-jet pump and immersed in an oil bath,140 parts (1 mole) of phenylphosphonic acid are heated gradually to 200degrees centigrade (bath temperature) and are kept for about 48 hours to72 hours at that temperature and under vacuum. This treatment produces apolyphenylphosphonic acid with a degree of condensation of about 2,which can be verified by the loss of weight of the flask or byacidimetric titration (the titrata=ble acidity between the respectivecolorings of methyl orange and phenolphthalein greatly diminishes).After cooling, 1.5 to 2.0 moles of alcohol are introduced into theflask, with the operation being continued in the manner described inExample 1. There is obtained a phenylphosphonic monoester in the form ofits barium or calcium salt, described under Examples 1 and 2, withyields of 51 percent for the methyl monoester, 44 percent for the ethylmonoester, 33 percent for the propyl monoester, 22 percent for theisopropyl monoester, 40 percent for the butyl monoester, 27 percent forthe isobutyl ester and 22 percent for the amyl ester. These yields areclearly below those obtained with the oxides (Examples 1 and 2) but asin the Examples 1 and 2, one may recover all the phenylphosphonic acidwhich is not transformed into an ester, in the form of an alkaline earthmetal salt.

Example 4 140 parts (1 equivalent) of phenylphosphonic oxide and 84-to112 parts (1.5 to 2.0 moles) of propargyl alcohol are heated to 90degrees centigrade. One then isolates the monopropargylphenylphosphonateof barium or calcium in the manner already described in Example 1. It isillustrated by the'structural formula:

OM CeH5-P=O oorn-cz'cn and the yield is 70 percent.

By infrared spectroscopic examination, the presence of the CEC group isverified.

In the same manner, there is prepared in 90 percent yield,phenylphosphonic monoester of allyl alcohol All of these are newproducts. In the above formulas M=Ca or Ba Example 5 140 parts (1equivalent) of phenylphosphonic oxide and 120 to 161 parts 1.5 to 2.0moles) of 2-chloroethanol areheated for 16 hours at 120 degreescentigrade (bath temperature). After cooling, the excess of chlorohydrinis distilled off under vacuum and one isolates the barium salt of themono(Z-chloroethyl)phenylphosphonic acid,

phosphonic monoesters of halogenated alcohols mentioned below areobtained, with yields indicated.

. 6 Phenylphosphonic monoester of 3-chlorop'ropanol- (100 degreescentigrade, 16 hours) of the formula:

OH CaH5P O 00112015011201 Yield=84 percent.

Phenylphosphonic monoester of 4-chlorobutanol-l (15 degrees Centigrade,16 hours) of the formula:

OM c 0H5PO o CHzCHzCHzCHzCl Yield=65 percent.

Yield=5 6 percent.

Phenylphosphonic monoester of 3-fluoropropanol-1 (100 degreescentigrade, 48 hours) of the formula:

o OM CGH5 E OCHQCH CHzF Yield=40 percent.

Phenylphosphonic monoester of 2,2,3,3-tetrafluoropropanol-l (100 degreescentigrade, 48 hours) of the formula:

O OM ll CaH5-P 0 CHz-C F -C HF, Yield=60 percent.

All of these are new products. In the above formulas M=Ca or Ba Example6 140 parts (1 equivalent) of phenylphosphonic oxide (C H PO and 91 to124 parts (1.5 to 2.0 moles) of glycol are heated 48 hours at degreescentigrade (bath temperature). There is isolated the calcium or bariumsalt of the (2-hydroxyethyl-1)phenylphosphonic acid,

in the manner described in Example 1, with a yield of 60 percent.

Ina similar manner, except as it relates to the temperature for thetetramethyleneglycol, there are prepared the alkaline earth metal saltsof phenylphosphonic monoesters of diols mentioned below with the yieldsindicated:

Phenylphosphonic monoester of propanediol-1,3 of the formula: v

ll/ CBH5POCHRCH2CH2OH Yield=65 percent.

The phenylphosphonic monoester of butanediol-1,4 (here the reactiontakes place at 50 degrees centigrade, for

48 hours) of the formula:

oomomongomon Yield=72. percent.

Phenylphosphonic monoester of pentanediol-l,5 of the rmula:

O OBI CsH5P OCHzCHzCHzCHzCHzOH 'ield=77 percent.

In the case of butanediol-l,4 (tetramethyleneglycol), is temperatureshould not exceed 60 degrees centigrade, 1 order to avoid the formationof tetrahydrofurane in the hosphonation process.

Also, even if there is used a large excess of a phoshonating agent, onlyone group OH is phosphonated.

All of these esters are new.

In the formulas given M=Ca or Ba Example 7 140 parts (1 equivalent) ofphenylphosphonic oxide .nd 267 to 336 parts (3 to 4 moles) ofdimethylcolamine dimethylaminoethanol) are heated for 3 hours at 120legrees centigrade. The excess of dimethylcolamine is disilled off undervacuum and the residue is dissolved in 800 o 1000 parts of water. Thereis then added an excess )f calcium hydroxide in suspension in water withthe nixture being agitated for several minutes. After filtering, )nevolume of alcohol is added to the filtrate to comletely precipitate thecalcium phenylphosphonate still present. This is followed by furtherfiltration and evapora- :ion under vacuum. An amorphous residue isobtained, which, after being treated with boiling acetone, cooled andfiltered, yields a precipitate of calciumdimethylaminoethylphenylphosphonate. The formula of this compound is g 0030.5 CsHs-P OCHzCH2N(CH3)z and it was obtained in 50 percent yield.

In treating l-diethylaminopropanol-Z in the above described manner,there is obtained by evaporation under vacuum an aqueous alcoholicsolution of calcium (l-diethylaminopropyl-2 phenylphosphonate,

which is pure. The yield is 30 percent.

Example 8 140 parts (1 equivalent) of phenylphosphonic oxide and 152.5(2.5 moles) of colamine are heated at 180 degrees centigrade (bathtemperature) up to the point where the mass becomes homogenous. Then avacuum is created in the flash, which is kept at this temperatureovernight. After cooling, the reactive mass is dissolved in 800 to 1000parts of water with the addition of an excess of calcium hydroxide. Thismixture is agitated and an equal volume of ethanol is added. The liquidis filtered and evaporated dry under vacuum. The residue is treated withboiling alcohol and yields, after cooling, a precipitate of calcium(Z-aminoethyl)phenylphosp'honate,

C eH I? O 0 H20 HgN H2 in 40 percent yield.

Example 9 140 parts (1 equivalent) of phenylphosphonic oxide, 79 parts(1 mole) of pyridine and 111 to 148 parts (1.5 to 2.0 moles) of tertiarybutanol are heated for one night at degrees Centigrade (bathtemperature). A calcium or barium salt of t-butylphenylphosphonic acid,

CGH5P O C (CH is obtained in a yield of 60 percent by isolation in themanner described under Example 1.

Example 10 One mole of cetylic alcohol and one equivalent ofphenylphosphoric oxide are heated for 48 hours at 110 degreescentigrade. After cooling, the reaction mixture is taken up by ether andfour equivalents of triethylamine are added. The precipitate oftriethylammonium phenylphosphonate is filtered oil, Whereas thetriethylammonium salt of the monoester is soluble. The ether and excessof triethylamine are evaporated under reduced pressure and the residueis taken up by ether. This solution, treated with aqueous bariumchloride, yields a gelatinous precipitate which is filtered off, Washedwith water and then with acetone and ether, and finally dried in vacuumover P 0 The yield is 50 percent of pure barium cetyl phenylphosphonate:

When cetyl alcohol, used as starting material in the above example, isreplaced by one of the alcohols of the following formulas:

CH (CH CH OH CHF (CF CH OH and when using the described procedure, thefollowing barium phenylphosphonic monoesters are obtained:

OCH2(CHz)sCHs Yield:55 percent.

0 OBa Calls-ii OCH2(CH2)3CH3 Yield=23 percent.

ll/ CeHa-P O C H2(C F2) sCI'IFz Yield=5 5 percent.

Example 11 One mole of nerol, two moles of triethylamine and oneequivalent of phenylphosphonic oxide are mixed carefully (the reactionis exothermic and it is necessary to cool). After a few minutes themixture becomes homogenous. It is then heated at degrees centigrade for15 hours (with good agitation). After cooling, the reaction mass istaken up by anhydrous ether. The triethylammonium phenylphosphonate isfiltered off and the ether and the excess of triethylamine areevaporated under reduced pressure. The oily residue is dissolved inwater and the pH brought to about 5, by adding dilute hydrochloric acid.When an excess of a concentrated aqueous solution of calcium chloride isadded to the preceding solution, voluminous precipitate of the calciumsalt of the phenylphosphonic monoester appears. This precipitate, whichretains most of the unreacted terpene alcohol, is washed with water andthen with acetone which dissolves most of the retained alcohol. Toachieve the elimination of the retained alcohol, the precipitate isfinally washed with ether and then dried in vacuo over P The yield is 30percent of pure calcium neryl phenylphosphonate C1GH22O3PC34L5.

In a similar manner, the calcium salts of the phenylphosphonicmonoesters of geraniol and farnesol are obtained in 31 percent yieldeach.

Example 12 Three moles of menthol, 3 moles of pyridine and 3 equivalentsof phenylphosphonic oxide are mixed very carefully until the massliquefies and becomes homogenous. The mixture is then heated for 15hours at 70-75 degrees centigrade. After cooling, the reaction mixtureis taken up by water. This solution is introduced slowly and withagitation in normal hydrochloric acid (3 liters). The precipitate ofmenthylphenylphosphonic acid is filtered off, washed with water and thenheated at 60 degrees centigrade, in vacuo, for one night, in order toeliminate any trace of methanol which has been retained by theprecipitate. In this manner, pure menthyl phenylphosphonic acid, C H O'P, melting point 91 degrees centigrade, is obtained in an 81 percentyield.

In a similar manner, bornyl phenylphosphonic acid, C H O P, meltingpoint 104-105 degrees centigrade, is prepared from borneol in an 88percent yield.

Example 13 One mole of lactonitrile and one equivalent ofphenylphosphonic oxide are heated at 90 degrees centigrade for 46 hours.After cooling, the reaction mass is taken up by cold water and isquickly neutralized by barium hydroxide to a pH of 8.2 (turing ofphenolphthalein). One volume of cold alcohol is then added to completethe precipitation of the barium phenylphosphonate which is filtered offand discarded. The filtrate is evaporated and the residue is treatedwith acetone, filtered and dried. The dry residue is treated againseveral times with acetone in order to eliminate completely any trace oflactonitrile that would be still present, and dried in vacuo. The yieldof pure barium 2-carbamido-2-ethyl phenylphosphonate is 89 percent.

The a-nitrilo alcohols are transformed, under the described conditions,into the corresponding carboxarnidoalkyl phenylphosphonic monoesters,6-, 'yand (I-nitrilo alcohols yield the corresponding nitriolalkylphenylphosphonic monoesters.

In a similar manner are phosphonated the nitrilo alcohols of thefollowing formulas (yield of the barium salt of the monoester inparenthesis): NC-CII OH (35 percent); NC-C(CH OH (64 percent); NCCH CHOH (70 percent); NC-CH(CH )CH OH (34 percent); NC-CH CH CH OH (58percent);

(59 percent). The first two nitrilo alcohols yield the correspondingcarboxamidoalkyl phenylphosphonic monoesters and the other nitriloalcohols 08-, 'yand fi-nitrilo alcohols) yield the correspondingnitriloalkyl phenylphosphonic monoesters.

Example 14 One mole of anhydrous glycerol and one mole ofphenylphosphonic oxide are heated at 165 degrees centigrade until themass liquefies, and then for 20 hours at 120 degrees centigrade. Thereaction mass treated in the manner described in Example 1, yields crudebarium glyceryl phenylphosphonate. The crude salt is reduced to a veryfine powder which is heated for a few minutes with absolute alcohol.After cooling, one volume of acetone is added and the precipitatefiltered off, washed with alcohol and vacuum dried. These operations arerepeated on this product until pure barium glyceryl phenylphosphonate isobtained. The yield is 49 percent.

HOCI-I CHOHCH OP O) (C H OBa barium a-glyceryl penylphosphonate HOCH -CHOP (0) (C H (OBE ]-CH OH barium B-glyceryl phenylphosphonate.

The determination of the neighboring OH groups by the method ofMalaprade indicates that the product is composed of 51.5 percent ofbarium a-glyceryl phenylphosphonate and of 48.5 percent of the,B-derivative.

Example 15 Six moles of tribromoethanol and 4 equivalents ofphenylphosphonic oxide are heated at 90 degrees centigrade for 44 hours.After cooling, the reaction mass is taken up by cold alcohol or acetoneand poured immediately into two liters of water. This mixture isneutralized with barium hydroxide to a pH of 8.2 and diluted with waterto five liters. One volume of alcohol is added and the bariumphenylphosphonate is filtered ofif. The filtrate is evaporated todryness under vacuum, and the residue treated with ether (in order todissolve any traces of retained tribromoethanol) yields the pure bariumtribromoethyl phenylphosphonate having the following formula:

CBr CH OP(O)(C H )(OBa Yield, percent.

In a similar manner are prepared the phenylphosphonic monoesters oftrichloroethanol, trichloroisopropanol and trifiuoroetha'nol:

CCl CI-I OP(O) (C H )(OBa Yield, 88 percent.

CCl CH[OP(O) (C H (OBa )CH Yield, 78

percent. CF -CH OP(O) (C H )(OBa Yield, 81 percent.

Example 16 RP(O)(OM)(OCH (70%); 3)3 2 5)( 3) (16%); HOCH CH CH OP(O) (R)(OM) (70% ClCH CH OP(O) (R)(OM) (62%); 3( 2)s 2 H NCH CH OP(O)(R) (OM)(53%); (CH NCH CH OP(O)(R)(OM) (30%); H NCOCH(CH )OP(O)(R)(OM) (38%);NCCH CH OP(O)(R) (OM) (64%).

R represents the p-fiuorophenyl radical (FC H M represents an equivalentof an alkali earth metal and the yield is indicated in parenthesis.

p-Fluorophenylphosphonic oxide reacts with all the other alcoholsmentioned in Examples 1 to 15 to yield the correspondingp-fluorophenylphosphonic monoesters.

The p-fiuorophenylphosphonic oxide is prepared as follows according tothe equation:

38 grams (0.216 mole) of p-fluorophenylphosphonic acid and 64 grams (0.3mole) of p-fluorophenylphosphonyl dichloride are heated at 200 degreescentigrade for 1W0 hours (under light vacuum in order to facilitate theelimination of the hydrochloric gas evolved during the reaction). Theexcess of dichloride is distilled under reduced pressure. After cooling,the residue is heated with 400 milliliters of dry benzene until completedissolution. This solution is left for two days at 5 degrees centigradeand the precipitate (p-fluoro henylphosphonic oxide) filtered off. Thefiltrate is left again for two days at 5 degrees centigrade and a secondamount of p-fiuorophenylphosphonic oxide is filtered 01?. The operationis repeated until no further precipitation occurs (after concentrationof the solution to 200 milliliters). The precipitates are washed withbenzene and dried in vacuo at 60 degrees Centigrade. In this manner, 60grams of pure p-fluorophenylphospho'nic oxide, melting point 109-111degrees centigrade, are obtained (yield 88 percent).

(C H ,O FP) Calculated: F, 12.0 percent; P, 19.6 percent; equivalentweight, 158.1. Found: F, 12.4 percentj P, 19.3 percent; equivalentweight, 160.

What is claimed is: 1. A compound represented by the formula OM R-P o0R1 wherein R is selected from the group consisting of phenyl,halogeno-phenyl and nitro-phenyl, R is cycloalkyl, and M is selectedfrom the group consisting of alkali metals and alkaline earth metals.

2. A compound according to claim 1 in which M is an alkaline earthmetal.

References Cited UNITED STATES PATENTS 2,329,707 9/1943 Farrington etal. 260958 X 2,360,302 10/1944 EtZler et al. 260-958 X 2,792,374 5/1957Bradley et al 260-958 X CHARLES B. PARKER, Primary Examiner.

R. L. RAYMOND, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,358,057 December 12, 1967 Emile Cherbuliez et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 1, line 62, "centrigrade" should read Centigrade Column 5, lines53 to 56, the formula should appear as shown below:

C H -P=O OCH -CH=CH Column 6, line 9, "150" should read 50 Signed andsealed this 10th day of March 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents

1. A COMPOUND REPRESENTED BY THE FORMULA